Re: [zfs-discuss] Recovering data from a corrupted zpool

2009-03-27 Thread Richard Elling 

Matthew Angelo wrote:

Hi there,

Is there a way to get as much data as possible off an existing 
slightly corrupted zpool?  I have a 2 disk stripe which I'm moving to 
new storage.  I will be moving it to a ZFS Mirror, however at the 
moment I'm having problems with ZFS Panic'ing the system during a send 
| recv.


set your failmode to continue.  If you don't have a failmode parameter,
then you'll want to try a later version of Solaris.

I blogged about some techniques to deal with borken files a while back...
http://blogs.sun.com/relling/entry/holy_smokes_a_holey_file
http://blogs.sun.com/relling/entry/dd_tricks_for_holey_files
http://blogs.sun.com/relling/entry/more_on_holey_files

NB: if it is the receive that is panicing, then please file a bug.
-- richard



I don't know exactly how much data is valid.  Everything appears to 
run as expected and applications aren't crashing.


Doing an $( ls -lR | grep -i "IO Error" ) returns roughly 10-15 files 
which are affected.Luckily, these files ls is returning aren't 
super critical.


Is it possible to tell ZFS to do a emergency "copy as much valid data 
off this file system"?  

I've tried disabling checkums on the corrupted source zpool.   But 
even still, once ZFS runs into an error the zpool is FAULTED and the 
kernel panic's and the system crashes.   Is it possible to tell the 
zpool to ignore any errors and continue without faulting the zpool?


We have a backup of the data, which is 2 months old.  Is it slightly 
possible to bring this backup online, and 'sync as much as it can' 
between the two volumes?  Could this just be a rsync job?


Thanks



[root]# zpool status -v apps
  pool: apps
 state: ONLINE
status: One or more devices has experienced an error resulting in data
corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
entire pool from backup.
   see: http://www.sun.com/msg/ZFS-8000-8A
 scrub: none requested
config:

NAMESTATE READ WRITE CKSUM
appsONLINE   0 0 120
  c1t1d0ONLINE   0 0 60
  c1t2d0ONLINE   0 0 0
  c1t3d0ONLINE   0 0 60

errors: Permanent errors have been detected in the following files:

apps:<0x0>
<0x1d2>:<0x0>



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Re: [zfs-discuss] Recovering data from a corrupted zpool

2009-03-26 Thread Fajar A. Nugraha 
2009/3/27 Matthew Angelo :
> Doing an $( ls -lR | grep -i "IO Error" ) returns roughly 10-15 files which
> are affected.

If ls works then tar, cpio, etc. should work.
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[zfs-discuss] Recovering data from a corrupted zpool

2009-03-26 Thread Matthew Angelo 
Hi there,

Is there a way to get as much data as possible off an existing slightly
corrupted zpool?  I have a 2 disk stripe which I'm moving to new storage.  I
will be moving it to a ZFS Mirror, however at the moment I'm having problems
with ZFS Panic'ing the system during a send | recv.

I don't know exactly how much data is valid.  Everything appears to run as
expected and applications aren't crashing.

Doing an $( ls -lR | grep -i "IO Error" ) returns roughly 10-15 files which
are affected.Luckily, these files ls is returning aren't super critical.

Is it possible to tell ZFS to do a emergency "copy as much valid data off
this file system"?

I've tried disabling checkums on the corrupted source zpool.   But even
still, once ZFS runs into an error the zpool is FAULTED and the kernel
panic's and the system crashes.   Is it possible to tell the zpool to ignore
any errors and continue without faulting the zpool?

We have a backup of the data, which is 2 months old.  Is it slightly
possible to bring this backup online, and 'sync as much as it can' between
the two volumes?  Could this just be a rsync job?

Thanks



[root]# zpool status -v apps
  pool: apps
 state: ONLINE
status: One or more devices has experienced an error resulting in data
corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
entire pool from backup.
   see: http://www.sun.com/msg/ZFS-8000-8A
 scrub: none requested
config:

NAMESTATE READ WRITE CKSUM
appsONLINE   0 0 120
  c1t1d0ONLINE   0 0 60
  c1t2d0ONLINE   0 0 0
  c1t3d0ONLINE   0 0 60

errors: Permanent errors have been detected in the following files:

apps:<0x0>
<0x1d2>:<0x0>
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